Studies in the physiology of vitamins. III. A comparison of the effects of feeding extracts of muscle and yeast respectively

Abstract

In a previous communication 1 experiments were reported wherein it was shown that the feeding of extracts of rice polishings, wheat embryo, and navy bean to dogs which had been fed on a diet lacking vitamin-B resulted in a recovery of appetite which lasted for varying periods. Vitamin-B was suggested as the appetite-promoting factor in the preparations used. The present report concerns control experiments in which an extract lacking this factor was tested.

Commercial Liebig's extract of beef muscle and the extract of yeast vitamin as prepared by the Harris Laboratories were used for these experiments. Tests were made using the Liebig extract administered either with single large doses or with large doses repeated daily for as many as fourteen (14) days, the material being introduced by stomach sound in order to eliminate the taste factor. In another series of experiments the meat extract was mixed with the food which had been refused. The meat extract did not restore the appetite to such animals. On the other hand relatively small amounts of the yeast extract given by stomach produced a prompt recovery of appetite which lasted for from four (4) to nineteen (19) days depending on the amount administered.

Liebig's extract in doses such as were employed in these experiments promotes the flow of gastric juice in normal animak 2 This fact, together with our own observation that products containing vitamin-B do not promote the flow of saliva, pancreatic juice, or bile, 3 suggests that the recovery of the desire to eat in our animals is not to be ascribed to an increased flow of gastric juice.